Learning Forum

[Nick Fan]

Hello,
I used the Discrete Phase Model to simulate the trajectories of PM2.5 in indoor space, the volume injection is used to set 40,000 particles uniformly distributed in indoor space, and an air conditioner and an air purifier are used to dilute the particles inside the room. I use the RANS equations and the RNG k-ϵ turbulence model, with an explicit time integration method. I would like to ask what is the recommended range for the Courant number when setting it?

 

[Federico]

Best practices for explicit time integration would recommended to have a Courant number less or equal to 1.0 for accuracy and stability of the solution.

[Nick Fan]

Thank you for your reply, Federico.I apologize for the mistake in the initial conditions. Actually, I am using an implicit solver, not an explicit one. Could you please advise on the recommended range for the Courant number when using an implicit method?

[Federico]

The implicit solver is more flexible with Courant number and is generally more stable. Still, a Courant number closer to 1 will yield most accurate solution with better resolution of transient effects.

[Nick Fan]

Thank you for your valuable feedback, Federico.